when using the "ss -f inet -t" command to show the tcp socket information of
inet domain, we get the error message: "ss: no socket tables to show with such filter."
This patch can fix this bug.
Signed-off-by: Li Yewang <lyw@cn.fujitsu.com>
Signed-off-by: Stephen Hemminger <stephen.hemminger@vyatta.com>